1. Students are into groups of about four and are to design a catapult to demonstrate their understanding of levers and how they work.
2. Each group is to design a catapult that would be able to launch a masking tape ball 5 meters onto a target/bullseye.
3. Once designs are completed students choose their materials. They are to use things like masking/sticky tape, yoghurt containers, polystyrene trays, bottle tops, straws, boxes, cups, rulers and elastic bands etc.
4. Once constructions are completed each group is to share their catapult with the class. One at a time students are to test their designs to see whether they can launch their catapult to reach the 5-meter target/bullseye.
5. After a test run provide all groups with the opportunity to have another turn at seeing whether their catapult can launch the masking tape ball to reach the target/bullseye, 5 meters away.
6. Student then discuss why some worked better than others, the changes they would make to their designs if they were to make them again, how changing the position of the fulcrum may change what happens and how the amount of force affects the distance the masking tape ball will travel.
Lever
Levers use a stiff bar or rod balanced on a fulcrum to assist in the lifting and moving of objects.
Everyday machines that use a lever include:
Ø Pegs
Ø Pliers
Ø Scissors
Ø Wheelbarrow
Ø Crowbars
Ø Hammers
Activity
Catapult Competition1. Students are into groups of about four and are to design a catapult to demonstrate their understanding of levers and how they work.
2. Each group is to design a catapult that would be able to launch a masking tape ball 5 meters onto a target/bullseye.
3. Once designs are completed students choose their materials. They are to use things like masking/sticky tape, yoghurt containers, polystyrene trays, bottle tops, straws, boxes, cups, rulers and elastic bands etc.
4. Once constructions are completed each group is to share their catapult with the class. One at a time students are to test their designs to see whether they can launch their catapult to reach the 5-meter target/bullseye.
5. After a test run provide all groups with the opportunity to have another turn at seeing whether their catapult can launch the masking tape ball to reach the target/bullseye, 5 meters away.
6. Student then discuss why some worked better than others, the changes they would make to their designs if they were to make them again, how changing the position of the fulcrum may change what happens and how the amount of force affects the distance the masking tape ball will travel.